FIGS. 1-3 show a conventional sleeve-type anchor screw 30, and FIG. 4 shows a conventional wedge-type anchor screw 50. These conventional screws 30, 50 may be found in most hardware stores and are widely used. Turning first to the sleeve-type anchor screw 30 shown in FIGS. 1-3, the sleeve-type anchor screw 30 is made of four separate pieces (see FIG. 3) that work together to provide the function of anchoring the screw 30 into a material (e.g., masonry wall, concrete floor, cinder block, mortar). The sleeve-type anchor screw 30 has a shaft member 32, a sleeve member 34, a nut 36, and a washer 38. FIG. 3 shows the pieces separated and FIGS. 1 and 2 show the pieces operably assembles to form the sleeve-type anchor screw 30. The shaft member 32 has a threaded shaft portion 42 adapted to accept the nut 36. The sleeve 34 and the washer 38 are adapted to fit over the shaft member 32. The shaft member 32 has a transition portion 44 and a flat, blunt end 46.
Next, the typical method of installing and using the sleeve-type anchor screw 30 of FIGS. 1-3 will be described. The installation and use requires a minimum of three steps using three different tools and two devices (a drill bit and the anchor screw 30). First, a hole is drilled using a conventional masonry drill bit (not shown). The hole needs to be the correct diameter corresponding to the sleeve-type anchor screw 30 to be used. Otherwise, the sleeve-type anchor screw 30 will not work properly (i.e., not supporting the specified amount of force) or may not work at all. The masonry drill bit is usually driven with a hammer drill (not shown), but may be driven by a regular drill as well. In such case, the masonry drill bit is held by the drill chuck. Usually a conventional masonry drill is designed for many uses (to drill many holes). A typical masonry bit has a spade-shaped tungsten carbide tip mounted on the tip of a fluted shaft. The flutes help remove the debris (dust) from the hole during drilling. The shaft of the masonry drill bit is usually made from a relatively soft and flexible steel that differs from the hard, more-brittle cutting tip.
Once the hole is drilled, the second step is to insert the sleeve-type anchor screw 30 into the pre-drilled hole. Usually, the sleeve-type anchor screw will need to be driven into the hole (e.g., hammered) due to a desired snug fit. This step typically requires the use of a hammer to slide the sleeve-type anchor screw 30 into the hole. The object that is being fastened to the material (that the hole was drilled into) is usually held in place while the sleeve-type anchor screw 30 is inserted into the hole. If the object is large and/or heavy, this may require a second person to hold the object in place because the first person inserting the sleeve-type anchor screw may need two hands to insert the sleeve-type anchor screw (e.g., one hand to hold the sleeve-type anchor screw 30 and the other hand to swing the hammer).
After the sleeve-type anchor screw 30 is driven into the hole to a desired depth, the third step is to tighten the nut 36 and expand the sleeve 34 within the hole. During this step, the object will still need to be held by the first person and/or the second person. Typically, the first person must set down the hammer and pick up a different tool for tightening the nut. The nut may be tightened with any wrench, but is more preferably tightened with a power tool for speed and less effort, such as an impact gun and socket. As the nut 36 is tightened, the transition portion 44 of the shaft member 32 is drawn toward the sleeve 34 and engages the sleeve 34. The sleeve 34 of the sleeve-type anchor screw 30 shown in FIGS. 1-3, has longitudinal slots 48 formed therein. As the sleeve 34 engages the transition portion 44, the sleeve 34 is flared open at the slots 48. This is shown in FIG. 2. The more the nut 36 is tightened, the more the sleeve 34 is forced over the transition portion 44 of the shaft member 32. This causes the sleeve-type anchor screw 30 to be wedged into the hole very tightly. This wedging configuration within the material (within the hole) provides a very strong and secure anchoring of the sleeve-type anchor screw 30. For example, a typical ⅜ inch diameter sleeve-type anchor screw may be capable of holding up to 2000 pounds of pulling force on it when it is set in the material properly.
The conventional wedge-type anchor screw 50 of FIG. 4 has a sleeve 34 also, but the sleeve 34 in FIG. 4 is smaller than the sleeve 34 of the conventional sleeve-type anchor screw 30 of FIGS. 1-3. The conventional wedge-type anchor screw 50 shown in FIG. 4 is set and used with the same three-tool three-step process described above for the conventional sleeve-type anchor screw 30. Conventional wedge-type anchor screws 50 are preferred by some users, and may have a greater holding strength than a same-diameter sleeve-type anchor screw 30. However, many users find that the sleeve-type anchor screws 30 are easier to install with fewer jams while hammering the anchor screw into the pre-drilled hole.
This three-tool three-step process of setting conventional sleeve-type anchor screws 30 and conventional wedge-type anchor screws 50 is quite time consuming and requires a lot of man hours. Hence, there is a need for an easier way to set and use a sleeve-type anchor screw, while still providing the strength of the conventional sleeve-type anchor screw. It would be highly desirable to eliminate one or more of the tools needed to reduce the cumbersome process of switching tools at every step. Man hours or labor costs tend to be much more expensive than the cost of screws. Thus it also would be highly desirable to provide an anchor screw that can be set and used much faster, requiring fewer man hours, even if the screws cost slightly more than conventional anchor screws.